1. Technical Field
The present invention relates generally to memory cells and, in particular, to a phase change memory cell with improved phase change material.
2. Description of the Related Art
One main failure mechanism for phase change memory (PCRAM) devices is void formation after repeated cycling. If the void is formed on top of the bottom electrode, the PCRAM device is stuck in the open (high resistance) position and cannot be switched anymore to the low resistance state. This effect is most likely due to the large change in mass density between the amorphous and crystalline phase of the phase change material (typically 5-6%).